Continuous casting



Jan. 29, 1963 J. N. woGNuM 3,075,264

CONTINUOUS CASTING Filed Feb. 19. 1:?59

4 Sheets-Sheet 2' Jan. Z9, 1963 J. N. woGNUM 3,075,264

CONTINUOUS CASTING Filed Feb. 19, 1959 4 Sheets-Sheet 5 INVENTOR. 1`3gamas Wgnum wim/m P @man Jan. 29, 1963` J. N. woGNuM 3,075,264

CONTINUOUS CASTING Filed Feb. 19, 1959 4 Sheets-Sheet 4 @-15 Fig-1@ lig-9.17

UJiM/MQFDOQQQQL United States Patent O 3,',264 CGNTENUOUS CASTHNG James N. Wognum, 9369 S. Pieasant Ave., Chicago, Eil. Filed Feb. 19, 1h59, Ser. No. 794,3i4i 15 Claims. (Ci. 22-57.3)

This invention relates to the art of continuous casting of metals and alloys, and more particularly to an improved method and apparatus of the vibrating mold type for continuous casting in a more efficient manner.

For many years attempts have been made to commercially cast metals continuously in the form of continuous strip, bars, billets, tubes, or other shapes in order to gain the obvious economies resulting therefrom. A certain degree of success has been obtained commercially, but most of it has been in the non-ferrous field With only a small amount of success obtained when using iron and steel, and then only with higher grade alloy steels which ordinarily are more homogeneous due to a finer grain structure, and greater freedom from gas occlusion.

Apparatus has been provided for continuous casting in which a single peripherally closed mold having a central `passage through which the casting is withdrawn is reciprocated longitudinally of the travel of the cast metal. Separate means is provided for continuously withdrawing the cast metal in one direction while the movement of the mold is iirst in the same direction as the cast metal and then in a reverse direction against the movement of the cast metal.

One of the most prevalent difficulties when continuously casting with this apparatus as Well as with others has been the frictional drag and adherence of the solidified metal against the Walls of the mold. This adherence and friction has been so great at times that the first solidified thin shell of the casting within the mold is ruptured by the high tension required to draw the casting through the mold. This has created a very rough casting surface and sometimes rendered the coating withdrawing mechanism inoperative and thereby interrupted the entire operations of the casting machine until the mold walls have been cleared of the hardened metal. This condition has been partially alleviated by the use of various lubricants on the inside of the mold with only varying degrees of success.

Alleviation of this problem has been sought in another Way, as evidenced by Welblund, U.S. Patents Nos. 2,284,- 703 and 2,284,704, by providing a moid divided longitudinally into two halves which are given a small amplitude vibration transversely to the direction of travel of the metal being cast, the frequency of vibration being suggested in the range of about 1Gb to 1500 vibrations per minute. With this apparatus, as in others, separate means is required to pull the strip through the mold because the mold sections themselves do not provide any propelling force or motion for propagating the casting. In fact, as the casting is withdrawn, it is longitudinally retarded along its surface at the time intervals when it is in contact with the reciprocating mold halves during the cycle portions when the mold halves are brought toward the casting.

'It is the principal object of this invention to provide an improved method and apparatus of the vibrating mold type for continuous castings wherein the mold halves or sections are provided with both transverse and longitudinal reciprocating movement combined in a harmonic or orbital type vibratory movement or variations thereof, such movement causing the mold sections themselves to repeatedly Iihd Patented dan, 29, i963 contact and propagate the casting on their forward strokes in either longitudinal direction depending upon the angular direction of the orbital paths of movement of the mold sections, but allowing the'mold sections to be out or" contact with the casting onvtheir return strokes to thereby minimize sticking and adherence of the casting to the mold sections.

It is another object of this invention to provide an improved method and apparatus of the vibrating mold type for continuous'casting wherein the frequency of vibration of the orbital movementof the mold 'sections is extremely high as compared yto anything used heretofore and of very small amplitude, so as to minimize casting surface efects and to minimize the adherence of the casting to the mold side walls. i

It is still another object of the invention to provide an improved continuous Vcasting apparatus of the vibrating mold type in which improved means are used to cause vibration of the mold sections.

It is another :object of the invention to provide an improved continuous casting apparatus of the vibrating mold type in which the mold comprises a plurality of sections which can be vibrated While all of the mold sections remain in contact with each other in order to maintain a peripherally closed mold and thereby prevent leakage of tiuid metal transversely between the mold sections.

It is another object of this invention to provide a continuous casting apparatus embodying improved means for continuously feeding lubricant to the strip being cast.

Other objects and advantages of the invention should become apparent by referring to the accompanying drawings in which FIG. l shows a top plan view of the main portions of a preferred embodiment made according to the invention of one form of a continuous casting apparatus for casting billets;

FG. 2 shows a front elevation of the apparatus shown in FiG. 1;

FEG. 3 shows a sectional view as viewed along line 3-3 of FG. 2 and particularly shows a means used to vibrate the mold sections of the apparatus;

FiG. 4 shows a partial'sectional view along the line 4 4 of FIG. 3 and shows further a means used to vibrate the mold sections;

FIG. 5 shows a perspective View of apparatus substantially identical to that as shown in FIGS. l through 4;

FIGS. 6 to 9 show a few of the possible mold section shapes which can be used with the apparatus of FIGS. l t0 5;

FIG. l0 shows a perspective view partially cut away and in partial section of an embodiment of the invention which is used to cast strip;

FIG. ll shows a partial sectional view of the upper portion of the apparatus shown in FIG. l0;

FIG. l2 shows a sectional View of one mold section shown in FIG. l0 and particularly shows the Water cooling duct;

FIG. 13 shows a sectional perspective view of a third embodiment of the invention which is used to cast metal vertically upward; and

FIGS. 14 to i8 show partial sectional views of some of the possible shapes which can be cast in the apparatus of FIG. 13 and also shows the shapes of the inner portions of the mold sections required to make the shapes shown.

A preferred embodiment of the invention as shown in FIGS. l. to 4 comprises a support frame l which is mounted in -a position above the floor or ground where the apparatus is to be located. This support frame 1 is supported in la fixed position relative to its general location. Resting on the upper surface 1a of but not connected to the support frame 1 is a mold 19 composed of four mold sections 2, 3, 4 and 5 which are generally rectangularly block shaped. These sections are each provided with two corners 2a, 3a, 4a and 5a, respectively, which are cut at forty-five degree angles, and these sections are positioned in the formation of a cross as shown in FIG. 1 with the adjacent of the corners 2a, 3a, 4a and 5a in abutting relation.

Molten metal 11 is poured into the space 12 which is the central rectangular opening between the mold sections 2, 3, 4 and 5i. As the metal passes through the opening 12, it gradually solidilies and emerges con-tinuously below the mold sections in the regio-n 13 as a solidified cast billet or strip 18. Two feed rolls 14 are suitably iournalled on shafts 15 with their peripheral surfaces 16 aligned to contact the two opposite surfaces .17 fof the billet l. These rolls 14 are power driven by conventional means not shown in Vorder to control the speed of withdrawal of the billet 18 from between the mold sections, even though, in a manner to be described, the mold sections themselves propagate the billet through the mold.

Extending ythrough each mold section 2, 3, 4 and 5 are three circular apertures 20 which are provided with a plurality of roller bearings 21 which are spaced from each other longitudinally. The outer races 22 are press fit into the apertures 20 and are thereby held stationary with respect to the mold sections. The inner races 23 of the bearings 2.1 in each aperture 20 are provided with a hollow 'tubular shaft 24 passing through their central openings land these inner races 23 permit rotation of the shaft 24 relative to the m-old section. The spacing of the bearings 21 is provided by means of disc shaped eccentrically weighted bobs 25 'which are mounted in fixed positions on the shaft by means of keys 26. The eccentric weights 27 on Vthese bobs 2S protrude laterally as shown in FIGS. 3 Iand 4. However, other shapes are possible. It is only necessary that there be eccentric weighting of each bob 25. For example, another manner of obtaining the proper eccentric loading is by providing a symmetrical circular disc 4and drill a hole or holes through one portion of the margin.

The mold sections 2 and 4 are each provided with only two bobs 2S and three bearings 21 while the mold sections 3 and 5 are each provided with three bobs 25 and four bearings 21. This is because of their respective widths |as determined by the dimensions of the billet being cast. Also, each mold section is provided with three sets iof shafts 24 and bobs 2S. A larger or smaller number of sets can be used depending upon the length of the mold. If only one set is used on each section, extra stabilizing means are required to maintain the mold sections in their proper vertical planes without relative angular movement as will be explained.

Each hollow shaft 24 is provided with an internally splined mid region 28 which is mated with the externally splined end 29 of a shaft 30 which is reduced in diameter away from the splined end 29 so as to be readially spaced from the internal wall of the shaft 24 except at the splined connection. Each shaft 30 extends out of its shaft 24 and is joined by a coupling 31 to the shaft 32 of an electric motor 33. Although la separate motor may be used for each shaft 3% as shown, the shafts can be geared or chain driven together from a single motor, or else four motors can be used, one for the shafts of each mold section, any of these arrangements being of conventional form and obvious to one skilled in the art. lf one motor is used, all shafts will necessarily rotate in synchronism. If a plurality of motors are used, it is essential, as will be explained, that they be synchronous, and appropriate synchronous electric motors are available as standard purchased parts.

When the shafts 30 are rotated by the motors 33, the shafts 24 and the boos 25 attached thereto are rota-ted. Due to the eccentric weighting of the bobs 25, when rotated, they cause the mold sections 2, 3, 4 and 5 to vibrate in orbital paths. The orbital paths of the mold sections are synchronized in such a way that their corners 2a, 3a, 4a and 5a are always in contact. This is accomplished by having each section orbiting in an opposite direction to the section opposite it and by having each pair of opposite sections 2 and 4 orbiting 180 degrees out of phase with the other opposite pair of sections 3 and S. The effect is that sections 2 and 4 approach each other as sections 3 and 5 separate and sections 2 and 4 separate while sections 3 and 5 approach each other. The intermediate positions of the mold sections are as shown in solid outline in FIG. 1 while one set of extreme positions are indicated there by phantom lines, the extreme position shown being when sections 2 and 4 are closest to each other and when sections 3 land 5 are farthest from each other. The other extreme position (not shown) would be when the sections 2 and 4 are farthest `apart and when the sections 3 and 5Y are closest to each other. Since the orbital amplitude should be very small, in the order of only a few thousandths of an inch, obviously the relative positions of the molds are exaggerated. This is done for pictorial convenience only since a few thousandths of an inch difference could not be readily apparent on the drawings otherwise.

The particular type of circular or orbital motion of the mold sections is such that opposite mold sections 'are brought into contact with the billet or strip being cast while the sections are moving toward each other and d-ownwardly. Before the bottom of their stroke, the sections move away from each other and the billet, and they, af-ter reaching bottom, rise upwardly on a return stroke in a direction opposite to the direction of travel of the billet when out of contact with it. Upon this return stroke, the sections reach a maximum height as they again return toward each other and toward the billet and nally reengage it. It is on these forward strokes that the billet is actually moved or propagated forward by the mold sections. By having the mold sec- -tions cycling in opposite pairs at a 18-0 degree out of phase relationship, -as described, it is possible to have longer total eng-agement of the billet with mold sections than if only two mold sections are used at the same cycling frequency.

As to the frequency of cycling, it appears that a frequency of from 5000 to 50,000 cycles per minute with an orbital amplitude of up to about .020 inch will give good results and, the higher the frequency the better the result. The manner of adjusting the frequency is by using different motors 33 or by reducing or stepping up the output speed by standard gear or other well known mechanisms. The amplitude of movement can be regulated by using different bobs 25 which are eccentrically weighted by different amounts. The amplitude would then be a function of both frequency and the amount of eccentric weighting.

Although the feed rolls 14 are not used to propagate the billet since the mold sections do that, they tend to stabilize the forward motion of the billet and it is preferred that they tend to withdraw the billet at the same speed as it is propagated by the mold sections. For convenience the rolls 14 can be connected to a variable speed drive means which can be Varied in accordance with the propagating speed of the billet.

So far, only four mold sections have been described for casting a billet of rectangular cross section as diagrammatically shown in FIG. 6. However, the apparatus can f be modified to produce other shape billets as shown in FIGS. 7 through 9. FlG. 7 shows the mold section shapes that may be used to produce an elliptical shaped billet 34,.

FlG. 8 shows the mold section shapes for a circular billet or rod 35 while FIG. 9 shows the mold section shapes that could be used for an octagonal billet 36. lt is bvious that only four mold sections are required even for the billet 36, but eight are shown for illustration as to how a larger number than four can be used if desired. In such a case, each opposite pair of mold sections wouldbe orbited togetherin the same phase relation, but each adjacent mold secton would be orbited 90 degrees out or" phase with the one adjacent to it. The overall eiiect would, however, be the same. The angular contacting corners would remain in contact with each other at all times to prevent spillage transversely between the mold sections.

ln all of the mold sections shown and described so far, it is essential that cooling means be provided in order to maintain the proper temperature of the mold. The cooling medium can be water or other suitable coolant which is circulated through U-shaped passages 37 provided in each mold section. Five such passages are shown for the mold section 5, but any desired number can be used.

An alternative form of the structure shown in FlGS. 1 to 4 is shown in FIG. 5. ln PEG. 5, the similar or identical members are the support frame 1, the four mold sections 2, 3, l and 5 which have included in them the idenlical mold vibrating means shown in FIGS. 1 to 4, and the two feed rolls 13 and 1d.. The additional or different members are the two vertically mounted springs 6 and the four horizontally mounted springs '7 for each mold section, and the four spring retaining walls S, one adjacent each moid section. These walls d are rigidly secured to the upper surface la of the support frame 1 and are provided with recesses 3a into which the outer ends of the springs 7 are positioned. The inner ends of the springs I are positioned within recesses 'a in the mold sections 2, 3, d and 5'. These recesses da and 7a retain the springs '7 in horizontal alignment and sufriciently maintain them located in their horizontal positions. The vertical springs are retained by means of opposed recesses on in the support frame Il and recesses 6b in the mold sections 2, 3, l and 5i.

The su `port of the springs 6 keeps the mold sections 2, 3, 4 and at all times above the level of the support frame i while the support from the springs 7 keeps the mold sections separated from the retaining walls The purpose of the springs is essentially for maintaining the mold sections Z, 3, i and 5 supported on cushioned means for permitting fully responsive movement to the orbital vibration imparted to the mold sections during operation of the equipment with minimum wear and damage to the equipment due to the vibration. ln the embodiment of FIGS. l to 4, since the mold sections Z, 3, 4 and 5 rest directly on the rigid support frame i, the vibration tends to impart more wear and da nage to the equipment. ln the embodiment of 'HSS l to 4 this can also be minimized, however, by providing cushioned supports between the support frame i and its rigid support. The cushioned supports can, for example, be either springs or rubber cushions, or any other resilient means.

In FIG. 10 is shown another embodiment of the invention which is particularly adapted for the continuous casting of strip which may have substantial width but may be relatively thin. In such a situation, only two mold sections 38 and 39 are required. These sections are each provided with one hollow shaft d@ which is identical to the shafts 2e of FIG. 3 and this shaft du is provided with weighted bobs, bearings and a connection to a drive shaft 4l identical to those associated with the apparatus of PEG. 3. Each drive shaft 4l is connected by a coupling d2 to the shaft of a synchronous electric motor 43 which is mounted on a fixed support de. Only one shaft di? and set of bobs and parts are shown for each mold section because the sections are connected to the inner ends 45 and 46 of two flat wedge shaped support arms 47 and port for the two mold sections 3S and 39, springs 3&1

and 39a are provided. These springs or equivalent resilient supports are preferably mounted on a rigid frame support connected to the fixed frame members 53 and S4. ln addition, two more springs 51a and 52a or equivalent resilient means are suitably mounted against the linkages 51 and 52 to urge the two mold sections 3S and 39 toward each other. The mold sections are limite in their movement toward each other, to thereby maintain 'proper spacing between them, by keeping the corners Sib and 52b of linkages 51 and 52 squared to limit pivotal movement of the linkages Si. and S2.

Even though this particular arrangement is shown, it

-is possible to use a plurality of sets of shafts and bobs in each mold section as shown for the apparatus of FIG. 5

and, in that case, the mold sections would be supported on spring cushioned supports rather than on the arms i7 and 4S. Conversely, the type of supporting structure of FIG. 10 could be used in place of that shown for the apparatus of FIGS. 1 through 4.

The front faces 55. and 56 of the mold sections 3d and 39 are spaced apart by the approximate thickness of the strip 57 to be cast and side guides 58 and 59 are positioned against the sides of the mold sections in order to prevent transverse flow of metal. These guides 58 and S9 are held by suitable means (not shown) against the mold sections, but not fastened to them in order to permit the free orbital movement of 'the sections.

Two feed rolls 6i) and 6i are mounted to drive the strip 57 at the same speed as it is propagated by the mold sections and are similar in all respects to the rolls 14 of FlGS. 1 through 5. As shown best in FIG. ll, the tundish 62, which is positioned above the mold sect'ons and into which the molten metal 63 is poured, is provided with recesses 64 on its under surface to provide spaces 65 into which a mold lubricant can be poured. Conduits 66 are provided for guiding the lubricant from receptacles 67 to the spaces 65. The receptacles 67 are mounted on the fixed frame members 5d and S5. Also, at the top adjacent surfaces of the mold sections are provided serrations or saw toothed cuts 18 which cause iiow of the lubricant from the spaces 65 into the mold where the lubricant can run down the front faces 55 and Se of the mold sections to lubricate the strip and further assist in preventing sticking of the strip on the mold section faces. These serrations also hold back the molten metal and prevent it from leaking out between the lower surface of the tundish '62 and the upper surfaces d8 and 69 of the mold sections.

Similar to the U-shaped passages 37 of the apparatus of FGS. 1 to 5, these moldsections 3S and 39 are provided with passages 7d (FIGS. 11 and 12) through which coolant iiuid can be passed.

Both embodiments shown so -far are adapted for continuously casting billets or strip as they are moved vertically downward. When so doing, it is not possible to produce anything but solid shapes. However, it is known that hollow shapes can be continuouslyk cast by arranging the cast object to 4be movedor propagated vertically upward while it takes molten metal from a tundish positioned below the mold sections. The orbital mold motion of this invention is equally applicable to such a type apparatus and one form of it is shown in FIG. 13.

The support frame 71 for it is carved out or cast with a modified tl-shaped dish 72 having two chambers 73 and 74 connected by a conduit 75 between them. Molten metal '76 is poured into the chamber '73 as required and it pours through the conduit 75 to ll up the chamber 74. In this way, the huid metal in chamber 73 provides -a pressure head for forcing the iluid up to a particular level in chamber 74.

Mounted on sloped walls 77 of the chamber 74 is a disc shaped member 7S which may be manufactured of refractory material or metal which is of less specific gravity than the molten metal 76 so that the member 78 will ordinarily oat on the molten metal. The upper sur-face of the member 78 is also provided with dished walls 79 upon which four mold sections Sil are positioned. (Because of the sectional view, only three sections are shown.) Although not shown in FIG. 13, the mold sections can be suitably vibrated in orbital paths by power from synchronous motors such as 33 and t3 which are connected to drive internal mechanisms 81 similar to those on the apparatus of FGS. l to 5. Also, suitable coolant passages 82 can be provided as required.

The purpose of the lioating disc member 78 is to permit slight movement thereof downwardly when the mold sections are orbited to allow for the movement of the sections.

In operation, the top level 83 of the molten metal in the chamber '74 will remain approximately at the same level as the upper surface 84 of the molten metal. As the mold sections are vibrated, the metal in the regions: 85 adjacent the lower inner surfaces or faces 86 of the mold sections is carried upward by the orbital movement of the mold sections. The metal progressively hardens or freezes from the faces 86 radially toward the center of the mold to provide a progressively thicker hardened wall while the metal remains molten between the wall. Then, as the hardened wall is propagated above the natural level 83 of the molten metal, the molten metal is left behind and a hollow tubular shape emerges, the thickness of the wall of the tube being dependent upon the speed with which the mold sections propagate the cast metal upwardly. The greater the speed, the thinner the wall because less time is allowed for heat transfer and consequent hardening of the wall.

Feed rolls S7 are mounted to be driven above the level of the mold sections 80 in order to support the weight of the finished tubing and synchronize the withdrawal of the tube with the speed of propagation provided by the mold sections.

The particular circular mol-d shape of FIG. 13 is shown in FIG. l and other tubular or non-tubular shapes can be produced by the apparatus of FIG. 13 as exemplified by, but not restricted to, the shapes shown in FIGS. 14, 16, 17 and 18, provided the mold sections are appropriately changed in shape.

l claim:

l. Apparatus for continuous casting of metal comprising, a mold having a cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of a plurality of mold sections located at all times around the cavity with said inside surfaces disposed at all times substantially parallel to the longitudinal axis of the cavity, one of Said open ends of said cavity being a receiving end through which molten metal can be introduced into said cavity and the other of said open ends of said cavity being a discharge end through which said i metal can be progressively dischargedfrom said cavity,

vibrating means connected Vto vibrate said mold sections to cause a selected plurality of opposed surfaces of said inside surfaces of said sections to vibrate in closed paths, each path consisting of two consecutive portions of movement, the rst portion of movement involvingmoving each of said opposed inside surfaces of the sections toward said longitudinal axis of said cavity and forward Y toward the discharge end thereof to provide a driving force on the metal casting to propagate it through the cavity, the second portion of movement involving moving each of said opposed inside surfaces in retraction away from said longitudinal axis and in return movement toward the receiving end of said cavity while said metal is in said cavity so that resistance to the forward movement of the metal by the inside Surfaces of the sections is minimized.

2. Apparatus according to claim l wherein said sections are arranged in radially opposed pairs, and means to cause said vibrating means to vibrate the sections of each said pair so that the inside surfaces of said pair vibrate synchronously with each other during their vibration.

3. Apparatus according to claim l wherein each of said sections is substantially in sliding contact along its lateral margins with the sections adjacent to it, the vibration of one section relative to an adjacent section being out of phase with the vibration of said adjacent section by an amount suiiicient to substantially maintain sliding contact between the lateral margins of adjacent sections and thereby tending to avoid leakage of molten metal between the lateral margins of the sections.

4. Apparatus according to claim l wherein said vibrating means comprises for each section an eccentrically weighted shaft journalled on that section and means for rotating said shaft whereby the eccentric weighting of the shaft as it rotates causes said vibration of said section on which the shaft is journalled.

5. Apparatus according to claim 1 wherein each of said sections is substantially in sliding contact along its lateral margins with the sections adjacent to it, the vibration of one section relative to an adjacent section being out of phase with the vibration of said adjacent section by an amount sufficient to substantially maintain sliding contact between the lateral margins of adjacent sections and there- |by tending to avoid leakage of -rnolten metal between the lateral margins of the sections, said vibrating means comprising for each section an eccentrically weighted shaft journalled on that section and means for rotating said shaft whereby the eccentric weighting of the shaft as it rotates causes said vibration of said section to which the shaft is journalled.

6. Apparatus defined by claim l characterized by, every alternate section in aV direction around the cavity constituting one set of sections and the remaining sections constituting a second set of sections, and means to cause said vibrating means to vibrate the sections of the sets so that the inside surfaces of each respective set vibrate synchronously with respect to each other through their Said two portions of movement.

7. Apparatus defined by claim 1 characterized by, every alternate section in a direction around the cavity constituting one set of sections and the remaining sections constituting a second set of sections, and means to cause said vibrating means to vibrate the sections of each set so that the inside surfaces of each respective set vibrate synchronously through their said two portions of movenient each of said sections being substantially in Sliding contact along its lateral margins with the sections adjacent to it, the vibration of one section relative to an adjacent section being out of phase with the vibration of said adjacent section by an amount suiicient to substantially maintain sliding contact between the lateral margins of adjacent sections and thereby prevent leakage of molten metal between the lateral margins of the sections.

8. Apparatus for continuous casting of a metal strip which is relatively wide as compared to its thickness cornprising, a mold having a cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of two mold sections disposed at all times substantially parallel to the longitudinal axis of the cavity and positionedat all times opposite each other by an amount approximately equal to the thickness of the metal to be cast, one of said open ends of said cavity being a receiving end through which molten metal can be introduced in to said cavity and the other of said open ends of said cavity being a discharge end through which said metal can be progressively discharged "from said cavity, vibrating means connected to vibrateA said mold sections to cause said inside surfaces of said sections to vibrate in closed paths of motion toward said longitudinal axis of said cavity and toward the discharge end thereof to provide a driving force on the metal strip to propagate it through the cavity and then in retraction away from said longitudinal axis and in returning movement toward .the receiving end of said cavity while said metal is in said cavity so that resistance to the forward movement of the metal by the inside sur-faces of the sections is minimized.

9. Apparatus according to claim 8 wherein said sections are provided with side guides bridging adjacent lateral margins of said sections to tend to avoid leakage of molten metal from between said lateral margins of the sections.

10. The method for continuous casting of metal comprising, introducing molten metal into the cavity of a mold of a type having the cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of a plurality of mold sections located at all times around the cavity with said inside surfaces disposed at all times substantially parallel to the longitudinal axis of the cavity, one of said open ends of said cavity beinu a receiving end through which molten metal can be introduced into said cavity and the other of sai open ends of said cavity being a discharge end through which said metal can he progressively discharged from said cavity, abstracting heat from the imolten metal as it passes through the cavity to cause the molten metal to solidify, and vibrating a selected plurality of opposed surfaces of said inside surfaces of said sections in closed paths, each path consisting of two consecutive portions of movement, the first portion of movement involving moving each of said opposed inside surfaces of the sections toward said longitudinal axis of said cavity and forward toward the discharge end thereof, the second portion of movement involving moving each of said opposed inside surfaces in retraction away from said longitudinal axis and in return movement toward the receiving end of sai cavity while said metal is in said cavity so that resistance to the forward movement of the Imetal by the inside surfaces of the sections is minimized.

l1. The method for continuous casting of metal cornprising, introducing molten metal into the cavity of a mold of a type having the cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of a plurality of mold sections located at all time around the cavity with said inside surfaces disposed at all times substantially parallel to the longitudinal axis of the cavity, one of said open ends of said cavity being a receiving end through which molten metal can be introduced into said cavity and the other of said open ends of said cavity being a discharge end through which said metal can be progressively discharged from said cavity, abstracting heat from the molten metal as it passes through the cavity to cause the molten metal to solidify, every alternate section in a direction around the cavity constituting one set of sections and the remaining sections constituting a second set of sections, synchronously vibrating the inside surfaces of each set of sections in closed paths, each path consisting of two consecutive portions of movement, and vibrating the first set of sections out of phase with the second set of sections so that the two sets alternately follow the two portions of movement, the rst portion of movement involving moving the inside surfaces of the sections toward said longitudinal axis of said cavity and forward toward the discharge end thereof to provide a driving force on the metal casting to propagate it through the mold, the second portion of movement involving moving said inside surfaces in retraction away from said longil@ tudinal axis and in return movement toward the receiving end of said cavity while said metal is in said cavity so that resistance to the forward movement of the metal by the inside surfaces of the sections is minimized,

l2. The method defined by claim ll characterized by, adjusting the vibration of one set of sections relative to the other set so that all of the sections remain substantially in side by side sliding contact to thereby tend to avoid leakage of molten metal between the sections.

13. Apparatus for continuous casting of metal comprising, a mold having a cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of a plurality of mold sections located at all times around the cavity with said inside surfaces disposed at all times substantially parallel to the longitudinal axis of the cavity, one of said open ends of said cavity being a receiving end through which molten metal can be introduced into said cavity and the other of said open ends of said cavity being a discharge end through which said metal can be progressively discharged from said cavity, vibrating means connected to vibrate said mold sections to cause a selected plurality of opposed surfaces of said inside surfaces of said sections to vibrate in closed paths, each path consisting of two consecutive portions of movement, the iirst portion of movement involving moving each of said opposed inside surfaces of the sections toward and into contact with the metal and longitudinally of the axis of the cavity to drive the metal forward toward the discharge end thereof to provide a driving force on the metal casting to propagate it through the cavity, the second portion of movement involving moving at least portions of each of said opposed inside surfaces in retraction away from contact with the metal and in return movement toward the receiving end of said cavity while said metal is in said cavity so that resistance to the forward movement of the metal by the inside surfaces of the sections is minimized.

14. Apparatus for continuous casting of metal comprising, a mold having a cavity extending longitudinally therethrough open at its opposite ends and formed by the inside surfaces of a plurality of mol-d sections located at all times around the cavity with said inside surfaces disposed at all times substantially parallel to the longitudinal axis of the cavity, one of said open ends of said cavity being a receiving end through which molten metal can be introduced into said cavity and the other of said open ends of said cavity being a discharge end through which said metal can be progressively discharged from said cavity, vibrating means connected to vibrate said mold sections to cause a selected plurality of opposed surfaces of said inside surfaces of said sections to vibrate in closed paths, each path consisting of two consecutive porti-ons of movement, the first portion of movement involving moving each of said opposed inside surfaces of the sections toward said longitudinal axis of said cavity and forward toward the discharge end thereof to provide a driving force on the metal casting to propagate it through the cavity, the second portion of movement involving moving each of said opposed inside surfaces in retraction away from said longitudinal axis and in return movement toward the receiving end of said cavity while said metal is in said cavity so that resistance to the vforward movement of the metal by the inside surfaces of the sections is minimized, a receptacle adjacent the mold for receiving molten metal and guiding it into the cavity of the mold, means for feeding a lubricant to the region between the receptacle and the mold, and feeding means on the mold moving in direct response to the movement of the mold for forcefully feeding the lubricant from said region to said cavity of the mold.

l5. Apparatus for continuous casting of metal comprising an open ended mold, a receptacle above the mold for receiving molten metal and guiding it into the cavity of 1 1 the mold, said mold being vibrated to alternately contract and expand in cross section in an orbital movement, means for feeding a lubricant to the region between the receptacle and the mold, and a projection on the mold for feeding the lubricant to the surface of the metal being cast, said projection extending from the Upper end of the mold and forcing the passage of lubricant to the surface of the metal being cast each time the mold is contracted during its orbital vibration.

-References Cited in the le of this patent UNITED STATES PATENTS Junghans Nov. 1, Weiblund et al. June 2, Sendzimir May 20, Tarmann et al. Oct. 5, Easton et al. Dec. 25, Goss July 7,

Bungerath et al. July 21, 

1. APPARATUS FOR CONTINUOUS CASTING OF METAL COMPRISING, A MOLD HAVING A CAVITY EXTENDING LONGITUDINALLY THERETHROUGH OPEN AT ITS OPPOSITE ENDS AND FORMED BY THE INSIDE SURFACES OF A PLURALITY OF MOLD SECTIONS LOCATED AT ALL TIMES AROUND THE CAVITY WITH SAID INSIDE SURFACES DISPOSED AT ALL TIMES SUBSTANTIALLY PARALLEL TO THE LONGITUDINAL AXIS OF THE CAVITY, ONE OF SAID OPEN ENDS OF SAID CAVITY BEING A RECEIVING END THROUGH WHICH MOLTEN METAL CAN BE INTRODUCED INTO SAID CAVITY AND THE OTHER OF SAID OPEN ENDS OF SAID CAVITY BEING A DISCHARGE END THROUGH WHICH SAID METAL CAN BE PROGRESSIVELY DISCHARGED FROM SAID CAVITY, VIBRATING MEANS CONNECTED TO VIBRATE SAID MOLD SECTIONS TO CAUSE A SELECTED PLURALITY OF OPPOSED SURFACES OF SAID INSIDE SURFACES OF SAID SECTIONS TO VIBRATE IN CLOSED PATHS, EACH PATH CONSISTING OF TWO CONSECUTIVE PORTIONS OF MOVEMENT, THE FIRST PORTION OF MOVEMENT INVOLVING MOVING EACH OF SAID OPPOSED INSIDE SURFACES OF THE SECTIONS TOWARD SAID LONGITUDINAL AXIS OF SAID CAVITY AND FORWARD TOWARD THE DISCHARGE END THEREOF TO PROVIDE A DRIVING FORCE ON THE METAL CASTING TO PROPAGATE IT THROUGH THE CAVITY, THE SECOND PORTION OF MOVEMENT INVOLVING MOVING EACH OF SAID OPPOSED INSIDE SURFACES IN RETRACTION AWAY FROM SAID LONGITUDINAL AXIS AND IN RETURN MOVEMENT TOWARD THE RECEIVING END OF SAID CAVITY WHILE SAID METAL IS IN SAID CAVITY SO THAT RESISTANCE TO THE FORWARD MOVEMENT OF THE METAL BY THE INSIDE SURFACES OF THE SECTIONS IS MINIMIZED. 